1366 - Incorrect integer value: '' for column 'customer_id' at row 1

insert into whos_online (customer_id, full_name, session_id, ip_address, time_entry, time_last_click, last_page_url) values ('', 'Guest', 'a60c379b4562303eedbd64ab81eb9e51', '54.198.246.164', '1563499552', '1563499552', '/account.php')

[XT SQL Error]